1. Field of the Invention
The present invention relates to satellite antennas, more specifically a satellite antenna capable of substantially vertical orientation.
2. Description of Related Art
There is a plethora of inventions related to microstrip lines generally and specially microstrip (also often called patch) antenna. Recent inventions relate to additional modules external to the patch antenna itself.
There is a plethora of inventions related to microstrip lines generally and specially microstrip (also often called patch) antenna. Recent inventions relate to additional modules external to the patch antenna itself.
Either some external modules are added to existing microstrip antenna device based on prior art technology or some additional active devices are included such as biasing of semiconductor substrates.
The present invention is based on the following strategies:                (1) User friendliness meaning easy mounting and “plug and play” approach, so that any layman can handle the mounting of the antenna and connection to any commercially available tuner without much technical effort.        (2) Minimising the cost of production as much as possible, incorporating commonly available materials, which are amenable for processing in the production of microstrip antenna and the associated substrates and conducting materials.        
With these two main points under focus, the technique described in this invention is based on inclusion of microstrip structures on the plane of the patch antenna itself and reinforcement of received signals using constructive interference based on positioning of reflectors on the plane of the patch antenna.
The present invention relates to a flat antenna for receiving digital or analogue signals from a satellite, arranged to be located in a substantially vertical position so that the antenna has an acute inclination angle with respect to the satellite's beam direction.
Conventional flat antennae need to be in a position such that the inclination angle with respect to the satellite's beam direction is 90 degrees. As the satellite's beam direction is seldom horizontal, these antennae cannot be mounted vertically.
A normal antenna includes conductive elements (receiving units in the form of patches) arranged in various topologies of rows and columns and a network of signal feed circuits interconnecting these elements. Part of the signal feed circuit usually has microstrip structures to compensate for phase delays in receiving the incoming radiation by these elements. The feed circuit geometry as a whole is designed in such a way that the signals received by selected groups of elements have the same phase before they are added together to provide a final output signal.
U.S. Pat. No. 4,963,892 shows a microwave plane antenna for receiving circularly polarized waves. This antenna comprises conductive antenna elements and conductive paths connecting the elements together.
The conductive paths which connect the elements have different lengths so that the main beam direction can be set in a plane including that of the antenna.
U.S. Pat. No. 5,661,494 describes a microstrip antenna for radiating circularly polarized electromagnetic waves comprising radiator elements with coplanar dual orthogonal microstrip feeds. The conductive paths in this antenna have again different lengths for phase compensation. If this antenna is to be used as a receiver, the plane containing the elements of the antenna should be perpendicular to the incoming radiation to obtain a satisfactory gain.